Obayashi's New Soil Treatment Cuts Soil Management Cost by 40%

Obayashi Corp., a major construction company headquartered in Japan, announced on September 25, 2008, the development of "Hisoguard", a soil treatment agent that can be used for arsenic immobilization, pH adjustment, and hardening of arsenic contaminated soils, all at once. It is commonly known that the arsenic soil contamination being derived from natural sources is widely found in Japan. When soil contaminated with arsenic is excavated during construction work, it should be handled as a surplus soil and properly managed as required by the law.

When such surplus soil is disposed of from the construction site, specific soil treatment should be afforded, including fixation of arsenic to prevent it from leaching into the adjacent groundwater, pH adjustment (potential of hydrogen ion concentration) to meet the waste acceptance criteria of disposal sites, and soil hardening to avoid the shifting of loaded soil during transportation. All of these procedures involve costs, and can add up to a considerable amount in total, thereby weighing heavily on development costs.

The new soil treatment system using Hisoguard can provide the above three kinds of soil treatment at once, reducing the treatment costs by as much as 40 percent compared to conventional methods.
It also allows for a wider selection of disposal sites, as it enables the soil treatment tailored to the waste acceptance criteria at a specific disposal site.